This invention relates generally to crystal oscillators, and more particularly, to an oscillator drive circuit having amplitude control.
Oscillators based on quartz crystals are widely used to provide stable timing signals for electronic circuits. Quartz crystals are passive components, so they must be actively driven to produce a useable signal. However, overdriving a crystal results in mechanical flexures within the crystal which reduce its accuracy. Overdriving also causes unnecessary power dissipation which results in errors due to accelerated aging.
Therefore, there is a need for a crystal oscillator drive circuit which provides precise amplitude control so as to maintain the accuracy of the crystal.